>It's my data, not their customers'.

Just because data is about you, that doesn't mean it is your data.

you may be minunderstanding the california consumer privacy act (ccpa). in the ccpa, personal data is defined as:

"Personal information is information that identifies, relates to, or could reasonably be linked with you or your household."

and, you do have the rights set forth in the ccpa (know, delete, correct, limit exposure, etc.) regarding that data.